Slip-releasing means for casing spiders and the like



Jan. 21, 1930. R. H. FOLSOM 1,744,381

SLIP RELEASING MEANS FOR CASING SPIDERS AND THE LIKE- Filed March 25,1928 INVENTORI Patented Jan. 21, 1930 UNITED STATES PATENT OFFICE ROBERTH. FOLSOM, OF LOS ANGELES, CALIFORNIA, ASSIGNOR TO JOHN GRANT, OF LOSANGE-LES, CALIFORNIA SLIP-RELEASING MEANS FOR CASING SPIDERS AND THELIKE Application filed March 23, 1928. Serial No. $564,071.

The present invention relates to casing spiders and similar devicesemployed in oil Well practice and embodying pipe engaging wedges orslips in conjunction with an annular body or ring.

In devices of this class the ring is provided with a tapered bore ofdecreasing diameter downwardly and the outer surfaces of the slips arecorrespondingly tapered.

The wedges are segmental in form and are arranged around the pipe orcasing between same and the ring so that the weight of the wedges andpipe act to crowd the wedges between the ring and pipe until the latteris fully suspended and held thereby.

W hen it is desired to release the Wedges for further movement of thepipe the usual practice is to lift the pipe slightly. Owing to the usualand practical angle of the said wedges and the bore of the ring, it isoften found that the Wedges remain jammed between the pipe and ring withthe result that the ring is lifted with the pipe. In such event thecommon and crude expedient is to strike the ring several blows with asledge to break the frictional hold beween the ring and wedges.

It is the main object of this invention to provide devices of the classdescribed which will act automatically to release the wedges should theybecome jammed to the extent that they do not release when the weight ofthe casing is relieved.

Other objects and advantages of the invention will appear hereinafter.

In carrying out my invention in its application to wedge and ringassemblies, I provide means arranged to move automatically under thewedges whenever the ring is lifted from the surface on which itordinarily reposes. Thus whenthe pipe and ring is again lowered theentire weight of the pipe comes upon the said means which in turnapplies such weight upwardly against the wedges to dislodge them. Saidmeans are so arranged as to hold the wedges in released and inoperativeposition until such time as the said means are Withdrawn from under thewedges.

In the accompanying drawings I have illustrated one practical embodimentof my in- 50 vention.

In the said drawings:

Figure 1 is a view in vertical section of the embodiment in use as acasing spider.

Figure 2 is a plan view thereof.

Figure 3 is a view in bottom elevation thereof.

Figure 4: is a View in side elevation showing the device in operationjust prior to dis lodgment of the wedges.

Figure 5 is a view similar to Figure 1 and showing the arrangement ofparts when the wedges have been moved automatically to inoperativeposition.

In the embodiment illustrated the numeral 8 on the drawings indicates aspider body of ring of usual arrangement and provided with the taperedbore 9 of decreasing diameter downwardly In said bore the slips orwedges 10 are arranged in the usual man nor to suspend oil well casing11. The ring is provided with the usual radial arms 12 and is shown asspanning an aperture 13 provid ed by a member 1 1. .Member 14: may be a1'0.-

tary table or any other suitable apertured structure employed in oilwell practice with the aperture 18 alined with the bore of the well.into which the casing 11, is to be lowered.

In conformity with a salient feature of the invention each arm 12 isprovided with a coextensive channel 15 which intersects the con tralbore 9 of the ring, as at 16. The slips and ring are so proportionedthat when the slips are in the normal operative position in which theyare shown in Figure 1, the lower ends 10 of the slips are disposed belowthe supper limits of the channels 15. In each channel a striker 17 isdisposed so as to be movable longitudinally of the corresponding channelin a horizontal path. A transvei e pin is provided in each channel andpass 3 thru a horizontal elongated slot in the corresponding striker.Thus each striker is not only secured in the channel for limitedlongitudinal movement but each striker has limited swinging movement ofthe corresponding channel. Upright pins 19. one at the outer end of eachstriker provide for manually moving the striker and each pin limits theswinging movement of the CiOlTQSDOllCllIlQ' striker to the angularposition in which the strikers are shown in Figure 4. The strikers maybe formed from short lengths of I beam stock or traction rail. Thelength of each striker is such that its forward end 17 can be moved intoclose contiguity with the easing and under the corresponding slip orslips. Usual practice requires only three slips whereas I have shownfour strikers in order to be assured of at least one striker for eachslip regardless of the position of the slips. The channels are deepenough to permit of the ring resting directly on the underlying surfacewhile permitting of unrestricted longitudinal movement of each strikerin its channel.

Normally the strikers are disposed in the retracted horizontal positionin which they are shown in Fig. 1, in which position they are entirelyinoperative and bear no part of the weight of the other parts. In Fig. 1the slips are shown in fully operative position. To release the slipsthe casing is raised slightly. Fig. 4 shows the casing so raised and inthis figure it. is assumed that the slips are jammed to the extent thatthe casing lifts the slips and ring with it.

\Vhen the ring is so lifted the inner ends of the strikers gravitatedownwardly and forwardly as permitted by the elongated slots 20 and thepins 21. Thus the forward ends 17 of each striker become disposed belowthe cor responding under surface 10 of the slips. The casing is nowallowed to descend so that the strikers assume the weight of the casingand become disposed between the member 14 and the slips. Thus the slipsare dislodged and forced into the inoperative position in which they areshown in Fig. 5. If, when the casing is raised as explained, the slipsare not stuck, the strikers may be manually shifted under the releasedslips to the position in which they are shown in Fig. 5. In thisposition the strikers hold the slips against descent so that they areheld inoperative dur ing any movement of the casing. IVhen the slips areagain to be put in operation it is only necessary to manually retractthe strikers to the position shown in Fig. 1.

\Vhile I have shown and described a specific embodiment of my inventionI do not limit myself to any specific embodiment or to any specificdesign or arrangement of parts and may alter the construction andarrangement of parts as I desire without enlarging the scope of myinvention, within the appended claims.

I claim 1. In a. device of the class described, a rin pipe engagingmeans having upward releasing movement in the bore of said ring, andmeans operable by lifting and subsequent lowering of said ring torelease said pipe engagmg means.

2. In a device of the class described a ring having a bore, pipeengaging wedges of friction angularit-y having upward releasing movementin said bore, and means operable by lifting and subsequent lowering ofsaid ring to release said wedges.

3. In a device of the class described, a supporting ring, pipe engagingwedges in said ring having vertical releasing movement witn regard tosaid ring, and wedge releasing means loosely carried by said ring anddisposed to gravitate, when said ring is lifted, below said wedges toproject below said ring.

4. In a device of the class described a ring, a supporting member onwhich said ring is loosely seated, pipe engaging means having upwardreleasing movement in said ring, and means operable by raising said ringfrom said member and subsequently returning said ring to said member, tomove said pipe engaging means upwardly with regard to said ring.

5. In a device of the class described, :1. ring, a supporting memberbelow said ring, pipe engaging we( of frictional angularity havingvertical releasing movement in said ring, and means operable by firstraising and subsequently lowering said ring to force said wedgesupwardly with regard to said ring and member respectively.

6. In a. device of the class described, a supporting member, a ringseated loosely on said member, pipe engaging wedges in said ring havingupward releasing movement with re gard to said ring, and means movablebetween said member and said wedges on upward movement of said ring withregard to said supporting member, said means preventing return of saidring to said member until said wedges are moved upwardly with regard tosaid ring.

7. In a device of the class described, a supporting member, a ringloosely seated on said member, pipe engaging wedges in said ring havingvertical releasing movement with regard to said ring, and wedgereleasing means loosely carried by said ring and disposed to gravitate,when said ring is lifted from said member, between said wedges and saidmember to prevent return of said ring to said member until said wedgesare released by up- 'a rd movement with regard to said rin 8. In adevice of the class described, a supporting member, pipe supportingwedges spaced above said member, a wedge supportin g ring restingnormally on said member and holding said wedges in such spaced positionwith regard to said member, and means oper able by lifting of said ringfrom said member to become disposed between said member and said wedgesto limit downward movement of said wedges when said ring is returned tosaid member.

ROBERT H. FOLSOM.

